Porous particles or pores of porous structures may be classified into three types based on their diameters: micro pores (less than 2 nm), meso pores (ranging from 2 nm to 50 nm) and macro pores (more than 50 nm). These porous particles capable of controlling pore sizes thereof are recently attracting attention, for they can be used in various fields including a catalyst, a separation system, a low-dielectric material, a hydrogen storage material, a photonic crystal, an electrode, etc.
The porous particles or porous structures can be produced by using various materials such as a metal oxide, a semiconductor, a metal, a polymer or carbon. Especially, a porous carbon particle has many advantages such as excellent surface characteristic, ion conductivity, corrosion resistance, low manufacturing cost, etc, and, thus, has wide range of applications to various fields.
However, the efficiency of the porous carbon particle may greatly differ depending on a distribution, a size, connectivity, a surface area, a surface characteristic of pores included in the porous carbon particle. Especially, the size of the pores needs to be controlled depending on the purposes of using the porous carbon particle. For example, in case of using a porous carbon particle for an electrode of a fuel cell, if a pore size of the porous carbon particle is excessively small, transport and diffusion of a reactant gas or the like may become difficult and an effect of using a catalyst may be degraded because polymer electrolyte cannot reach the inside of pores, though an impregnation amount of a catalyst material may be increased due to an increase of a specific surface area. Thus, ultimately, it may be impossible to produce a fuel cell having an improved performance.
Meanwhile, conventionally, it has been proposed using a template to produce the porous carbon particle. For example, a spherical silica or a colloidal crystalline array based on aligned agglomerates of latex polymer nanoparticles has been used as the template. For example, Korean Patent Application No. 10-2003-0087761 describes “Electrocatalysts for fuel cell supported by porous carbon structure having 3-dimensionally regularly arranged spherical pores of uniform diameter and their preparation method.” Specifically, this document describes a method of producing a porous carbon particle by using a template. Further, recently, there has been made efforts to synthesize a porous carbon particle including regularly arranged pores by template duplication using zeolite, a mesoporous material and a colloidal crystal. However, it has been observed that pores are not regularly arranged or distributed in porous carbon particles produced by using these conventional methods, and it has been impossible to control the size of the pores to be suitable for the purposes of usage. Further, in the conventional methods of producing the porous carbon particles by using the template, it has been difficult to simplify the production process and reduce cost.
In order to solve the aforementioned problems of the conventional methods of producing a porous carbon particle by using a template, the present inventors have found out that it is possible to produce a porous carbon particle while controlling a pore size easily by using a copolymer that allows selective cross-linking of a polymer particle and selective carbonization of a polymer particle. Based on this observation, the present inventors have reached the present disclosure.